Date Added: 30/10/2012
Date Updated: 28/11/2012
Sutureless aortic valve replacement in patients with severe aortic valve stenosis
Specialties: Cardiovascular disease & vascular surgery
Technology Type: Devices
Stage of development: Other
Stage of EAA: Assessment Complete
The symptoms of aortic stenosis include angina, syncope and heart failure. The 2006 American College of Cardiology and American Heart Association (ACC/AHA) clinical practice guidelines provide criteria for grading of aortic stenosis severity (see Table 1 in the report on the weblink).
In adults, the most common cause of aortic stenosis is acquired degenerative calcification of a normal valve, or a congenital bicuspid valve.2 As calcification progresses, the degree of cusp opening during systole becomes increasingly limited. Risk factors for degenerative calcific aortic stenosis include hypertension, hypercholesterolemia, diabetes mellitus, and smoking.
The Euro Heart Survey on valvular heart disease (VHD), conducted from April to July 2001 in 92 centres from 25 countries, included 5001 prospectively enrolled adults with moderate to severe native VHD.3 The aetiology of aortic stenosis was degenerative-calcific in the majority of patients (82%), rheumatic in 11 per cent, congenital in 6 per cent and post-endocarditis in the remaining 1 per cent.
Once symptomatic, patients without serious comorbid conditions are considered to be candidates for surgical AVR, the definitive treatment. AVR is traditionally an open procedure performed via sternotomy and requiring CPB. The valve prosthesis may be mechanical or biological and is implanted following resection of the native valve and annulus calcifications. In patients considered high risk for open surgery, transcatheter aortic valve implantation (TAVI) provides a minimally-invasive alternative that does not require resection of the diseased valve.4 Evidence suggests that TAVI is associated with more vascular complications and a higher incidence of stroke as compared to AVR, whilst AVR is associated with more major bleeding and new-onset atrial fibrillation as compared to TAVI.
Sutureless implantable valves are an alternative to traditional AVR and TAVI. These bioprostheses are mounted on self-expandable nitinol frames (Perceval and 3F Enable) or on expandable, cloth-covered stent frame (Intuity), which are implanted following resection of the diseased tissue. The procedure is similar to open AVR as sternotomy and CPB are still required; however, the sternotomy may be partial or full and CPB and aortic cross-clamp time may be reduced. Limited exposure of the operative field (partial sternotomy or minithoracotomy) usually makes more challenging the surgical procedure, including suturing and knotting the valve. This potential disadvantage is reflected in longer operative and cross clamp time compared to full sternotomy. Sutureless devices eliminate the need for many sutures as the valve is maintained in situ by the outward radial force of the frame or by the self-anchoring shape, which potentially makes valve deployment easier and faster.4